Verse 102

وَإِذَا كُنتَ فِيهِمْ فَأَقَمْتَ لَهُمُ ٱلصَّلَوٰةَ فَلْتَقُمْ طَآئِفَةٌ مِّنْهُم مَّعَكَ وَلْيَأْخُذُوٓا۟ أَسْلِحَتَهُمْ فَإِذَا سَجَدُوا۟ فَلْيَكُونُوا۟ مِن وَرَآئِكُمْ وَلْتَأْتِ طَآئِفَةٌ أُخْرَىٰ لَمْ يُصَلُّوا۟ فَلْيُصَلُّوا۟ مَعَكَ وَلْيَأْخُذُوا۟ حِذْرَهُمْ وَأَسْلِحَتَهُمْ وَدَّ ٱلَّذِينَ كَفَرُوا۟ لَوْ تَغْفُلُونَ عَنْ أَسْلِحَتِكُمْ وَأَمْتِعَتِكُمْ فَيَمِيلُونَ عَلَيْكُم مَّيْلَةً وَٰحِدَةً وَلَا جُنَاحَ عَلَيْكُمْ إِن كَانَ بِكُمْ أَذًى مِّن مَّطَرٍ أَوْ كُنتُم مَّرْضَىٰٓ أَن تَضَعُوٓا۟ أَسْلِحَتَكُمْ وَخُذُوا۟ حِذْرَكُمْ إِنَّ ٱللَّهَ أَعَدَّ لِلْكَـٰفِرِينَ عَذَابًا مُّهِينًا

And when you are amongst them, and you lead them in the contact prayer then let a group of them stand up to pray with you, the rest shall keep their weapons, so when you fall prostrate, they watch your back and the group who have not prayed, shall then come to pray with you and the others shall stand watch with their weapons. Those who have no faith would love to see you neglect your weapons and your equipment, so they can defeat you once and for all. Furthermore, you commit no error, if you are burdened by rain or an illness to lay down your weapons. However, you shall stand guard. Indeed, God promises the disbelievers a humiliating suffering.